What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Tire "egg" Question

T

toy4x4runner

1/2 ton status
Joined
Nov 3, 2004
Posts
122
Reaction score
0
Location
Tampa, FL
Had a real good shop balance my tires today with a Hunter GSP9700 balancer. they couldn't do "force" balancing b/c they said the MT lug pattern would give false readings. They recomended me ditching the stick on weights and doing weights on both edges of the rim. So We did that route. All tires got zero'd out before being put back on the Truck. however, the 4th tire, RR they told me was EGG shaped. :confused: What causes a tire to become Egg shaped? not keeping it aligned? not keeping it balanced? It's only been on the RR for 1 tank of gas. Last week I rotated my tires. so the Egg tire has been on the RF for the past 10 months really. should I get it shaved? warranttied? Now my 3 tires are smooth as glas... no joke... and the RR seems to hop a bit. uh boy... FYI my tires are 35x12.50R15 Dunlop Mud Rovers with 75% left and only 1.5yrs old.
 
how did they determine the tire was egg shaped? can you see it? does it vibrate now? did it before (the 10 months when it was up front?).

when the hunter guys set up our gsp9700 they said it would handle any tire you could physically fit under the hood. i have personally balanced at least 13 sets of 35 inch bfg at's, and at least 5 sets of various mud tires no problem on our hunter.

maybe they didnt want to use it cause it costs like $25k and are afraid to break it?


ryan
 
I don't know. they said the MT tread would give false vibration/force readings. they said the best thing for me was a Dynamic balance using the 6 lug adapter on the Hunger GSP9700. Right now... 3 tires are SOOOO smooth it's great! but that 1 RR "egg" tire is vibrating a bit. at lower speeds you can feel a bit of a "hop" up/down in that corner. You can visually see it. when they spun balanced it it was obvious. I'm supprised it doesn't cause more havick. I'm trying to get the thing warrantied.
 
we have a hunter balancer, not sure on the model, but I fit my 40" TSLs on it, I just have to hold the hood up a little but down just enough to kick it on and kinda tweak it sideways a smidge.
 
if the tire is new enough it should be warrantied. the "egg" shape is normally a belt seperation, where one of the belts allows air to get under it.

ryan
 
So is it dangerous to drive on an "egg" tire? I have my receipt from Tirerack.com. They're 1yr and 8 months old with 75% left. I already emaild Dunlop directly; waiting for monday. so I think I have to find a local authorized Dunlop dealer that will work with me. I'm gonna get the dial indicator out and see what the rim is giving me and the tire is giving me. Maybe I can find the High/low spots myself. I'm guessing a wrap of Duct tape will make a nice dial indicator contact surface on the tread. I'd like to make this egg tire my spare tire and get a new one shaved down to match the other 3. :)

MNorby- did you force balance your tires? or just spin them? b/c my little 32.5" tires fit fine under the hood. they said the MT tread design would cause false road force readings on the force balancer. so they just wanted to do a dynamic spin balance and put weights on the outer edges of the rim rather than stick on weights. like I said.... right now... 3 tires are smooth as glass.
 
I worked at Sears for a year and I have never heard of "force" balance. That something involving Yoda?

There's static balance and dynamic balance. Dynamic balances both sides of the tire to cancel out movement up and down and angular movement ( example "/" that type of movement on a tire that's "|"). Static just prevents up and down movement and generally is not as good as dynamic.
If you can visibly see the egg shape, that doesn't necessarily mean a belt is seperating. The only way to tell is to dismount the tire and check from the inside for soft spots....that is, unless the bulge is sticking out 2" from the tire...then that's pretty obvious.

Ask them to dismount the tire and check the inside for damage or seperated belts. I've even seen damaged beads cause bulges in the tire.

If belts are seperating, you should return the tire for manufacturer defect. If there's damage to the bead or from a rock (bruise), don't waste your time, becuase the bead damage isn't covered under road hazard anyway (it's the shops fault for installing it wrong) and the rock thing would only be covered under road hazard.
 
basically what a force balance is is a drum attached to the machine that presses down on the tire to simulate the surface of the road (tires arent round when rolling or mounted on the vehicle). the drum rolls with the tire and somehow the machine generates a road force measurement in lbs. gm says any more than 17 lbs is a bad tire. jaguar says 11. most of the 35 inch bfg at's i have spun are around 25-35 lbs of road force, with the worst one at 76 lbs. (which i had warrantied because it would have required over 6 lbs of stick on wieghts to balance).

ryan
 
The lugs of a MT might induce false road-force variations in the machine, giving the operator false indications.
But, Four Wheeler talks about getting every set of tires they test balanced and road-forced on the Hunter gadget.

Maybe shoot the Hunter folks an email and see what they have to say about it...
Hunter GSP9700 contact
 
toy4x4runner said:
MNorby- did you force balance your tires? or just spin them? b/c my little 32.5" tires fit fine under the hood. they said the MT tread design would cause false road force readings on the force balancer. so they just wanted to do a dynamic spin balance and put weights on the outer edges of the rim rather than stick on weights. like I said.... right now... 3 tires are smooth as glass.
Click to expand...


I do a spin dynamic balance on my 40" swampers and 315 yokohamas
 
Okay I'll chime in. We have 3 balancers at my shop (Discount Tire Co.) and 2 are the hunter road force. I have worked for DTC for over 3 years as a starving student being a tire tech (I am now in charge of the back room techs due to my experience). I have personally talked to hunter engineers, sales, and service. There are myths about the magic road force due to misinformed shop/tech personel.

Myth 1 - it makes a better balance: It does nothing for balance that a normal balancer can't do.
It does measre the amount of pressure it takes to make a tire near perfectly round. The numbers it puts out are in PSI so "17" is 17 pounds per sqaure inch of tread surface to make a round tire. The average car weighs enough to round out most tires under 22lbs, and a decent truck can handle 30lbs.

Myth 2 - The balancer knows all: The info the balancer gives is completly dependent on who/how it was set up. You need to measure the wheel run out, and take into account if the vehicle is hub-centric or lug-centric.

What the balaner can do for you. It can show the tech where the "heavy" or high spot is on the tire. After measuring the rim runout (can be done with the tire mounted on most wheels, if the wheel has a flat lip with no ridge the tire should be dismounted to test the wheel). This will then inform the tech where the "light" or low spot is on the wheel. With the heavy/light spots matched up it makes the tire more round. That is what the road-force is. The amount of force the road places upon the tire.


If the shop said it is egg shaped, it can mean it is spereated our a blem. Blems are safe tires but not up to the standards of a normal retail tire (do to a molding issue). We get the bigger MTR's (37's and 40's) that aren't round (blems) and sell them for about 70% of retail to wheelers or for spares.

How long ago did you get the tires? If they were bought from a real tire shop then would say take them back and see what they will do for you.
 
Got my Dunlop Mud Rovers from Tirerack.com 1yr 8 months ago. They have 75% of tread left. The tire has to have some kind of manufacture warranty I imagine. I'd like to make this egg tire my Spare... and get a pro-rated warranty replacement and have it shaved to match my other 3.
 
They probably won't let you keep it if they give you any credit on it.
 
You must log in or register to reply here.

Latest Posts

Top Bottom